Ubuntu One is a cloud storage service from Canonical that is very tightly integrated into Ubuntu. Although Ubuntu One is installed by default in Ubuntu, it is also available on Windows and Android. Ubuntu One is also used to store the music bought from the Ubuntu One Music Store.

Announcing the milestone, Canonical has also decided to change the plans on offer. Initially, 2 GB of storage was provided to everyone for free. Now, they have announced that they are more than doubling that to 5 GB. Current users of Ubuntu One will see their store size upgraded automatically.

Canonical has also changed the earlier Mobile plan to the Music Streaming plan. With the Music Streaming plan, users will get 20 GB of storage and unlimited music streaming to their Android and iOS device for $3.99/month. The Android app is already available in the Market (check out our review of the app here) and the iOS app is coming soon.